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Unformatted text preview: 11 Terminal-Oriented Computer Networks (cont.) Frame-based Error Control Techniques Header Information CRC CRC Information Header Terminal Header Information CRC Header Information CRC CRC Information Header CRC Information Header Terminal communication lines and analog switching equipment introduced errors in transmission error-control techniques were developed to ensure error-free communication example: Cyclic Redundancy Check (CRC) algorithm – an error-detection scheme (1) CRC is calculated based on frame header and payload (2) CRC is appended to frame (3) if receiver detects error, retransmission is requested some error-control techniques attempt to send enough redundant info to enable both error-detection and error- correction 12 1950s - 1960s: Terminal-Oriented Computer Networks 1960s – 1970s : Computer-to-Computer Networks: the ARPANET – first Wide Area Network (WAN) 1980s: Local Area Networks (LANs) 1980s: The Internet...
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- Winter '10
- Computer Networks, Computer network, packet switch